/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2013, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.classic.spi;

public class STEUtil {

  static int findNumberOfCommonFrames(StackTraceElement[] steArray,
      StackTraceElementProxy[] otherSTEPArray) {
    if (otherSTEPArray == null) {
      return 0;
    }

    int steIndex = steArray.length - 1;
    int parentIndex = otherSTEPArray.length - 1;
    int count = 0;
    while (steIndex >= 0 && parentIndex >= 0) {
      if (steArray[steIndex].equals(otherSTEPArray[parentIndex].ste)) {
        count++;
      } else {
        break;
      }
      steIndex--;
      parentIndex--;
    }
    return count;
  }
}
